The customer turned to us to validate a solution for discharging treated water in compliance with regulations, or for recycling clear water for reuse as washing water. The manufacture of plywood panels, using cleaning water for each gluing machine, generates 5000L of wastewater for our customer every day. Currently, the company has to call on an external service provider to dispose of its stored wastewater, with costs averaging €150 per m3. On the strength of their experience, Niskae’s engineers wanted to offer a coagulant-flocculant mono-reagent that would not only limit dosing and handling, but also a formulation that could be adjusted to the wash effluent, with the aim of increasing efficiency.

 Our customer has sent us two samples of its wastewater so that we can develop the coagulant-flocculant reagent best suited to the effluents encountered.

 The first sample of MUF glue wash water contained non-negligible concentrations of iron (1.24mg/L) and zinc (0.26mg/L), as well as 0.88% suspended solids (SS). For a minimum reagent dosage of 1.0g/L, we obtain a reduction in iron and zinc, both down to 0.04mg/L. Suspended solids were completely eliminated. What’s more, the solution presented to our Customer generates a low volume of sludge to be evacuated, only 10% of the volume of water to be treated, and the addition of the coagulation reagent does not modify the pH value, thus ensuring its stability.

 The sample of resorcinol glue cleaning water also contained significant concentrations of iron (0.46mg/L) and zinc (0.17mg/L), with 0.97% suspended solids. With the same reagent dosage of 1.0g/L, the iron concentration was reduced to below 0.01mg/L and the zinc concentration to 0.01mg/L. Suspended solids are also completely eliminated. The volume of sludge to be evacuated remains low, at just 2 to 3% of the volume of water to be treated, while the pH remains unchanged and stable after addition of the reagent. 

 Before treatment, the water from both samples was turbid, whereas after using the coagulant-flocculant formulation developed by NISKAE’s laboratory experts, it is now clean, clear and compliant with regulatory standards for possible discharge or reuse. The resulting sludge is non-sticky and easily dewatered, enabling it to be disposed of as waste.

Following analysis of the wash water samples supplied by the customer, NISKAE was able to propose a specific, tailor-made coagulation and flocculation solution, despite the presence of two separate glue effluents. The conformity of the discharge, the possibility of recycling the wastewater, reusing it as washing water, and the stability of the treatment will now enable our Customer to envisage the implementation of a highly efficient treatment process that remains simple to use, thanks to the use of a single flocculating reagent. Time savings, the elimination of storage and a substantial reduction in wastewater disposal costs are just some of the advantages of installing a Niskae water treatment and recycling microstation.